The present invention relates to a method of controlling the execution of multiple tasks in a microcomputer system.
Conventionally, when a CPU unit simultaneously executes a plurality of tasks in a microcomputer system, each program is obliged to deal with complex and massive contents. In addition, timing mechanisms needed for the task switching operation cannot be designed easily. To compensate for this, a microcomputer system uses the operating system (OS) to properly control the execution of multiple tasks. In other words, the microcomputer system is obliged to perform the switching operation (OS) for correctly executing a plurality of tasks. Conventionally, either a floppy disk or ROM containing the software operation system is made available for controlling the execution of multiple tasks. However, since such a software operating system is provided in a position above the program memory space controlled by the master CPU, the master CPU itself must execute the task switching operation, thus eventually restraining the user's program addresses to some extent. Although the concept of task control is basically free from the architecture of the CPU, if the task control is built into the operating system, the task control operation will become largely dependent on the CPU. As a result, if the needed operating system software is transferred to another CPU, it becomes necessary to also convert the operating system software so that it can be suited for use in the designated CPU, thus requiring an excessive handling operation to implement the needed conversion.